Where was the first Protestant church built?

Martin Luther started the Protestant movement when he sought to to reform the Roman Catholic Church's use of indulgences. The first Protestant communion was celebrated in St Mary's Church, Wittenberg, Germany, in 1521.
I think there is some confusion as to what the church is and what the church building is. The church is not the building, but the members of the congregation. That being cleared up, the question should be "Where was the first protestant church established?" or "Where was the first protestant church building built?" The contributor above has the correct to where and when the first protestant church was established.